1. Field of the Invention
The present invention relates to electron-beam length measurement technologies used in fabrication processes for such devices as semiconductor integrated circuits. More particularly, it relates to a high-accuracy electron-beam length measurement system and a calibration method therefor.
2. Description of the Related Art
In the conventional calibration method for the electron-beam length measurement system, as disclosed in Patent Document 1 for example, the calibration is performed using a moiré diffraction image which is acquired by scanning an electron beam on a two-dimensional arrangement lattice sample with a certain angle set thereto.